(a) The District Office is in Cleveland Ohio.

(b) The Ninth Coast Guard District comprise Michigan, New York north of latitude 42° N. and west of longitude 74°39′ W.; Pennsylvania north of latitude 41° and west of longitude 78°55′ W.; that part of Ohio and Indiana north of latitude 41° N.; that part of Illinois north of latitude 41° N. and east of longitude 90° W.; Wisconsin, except that part south of latitude 46°20′ N. and west of longitude 90° W.; and that part of Minnesota north of latitude 46°20′ N.

Sector Eastern Great Lakes' office is located in Buffalo, New York. The boundaries of Sector Eastern Great Lakes' Marine Inspection Zone and Captain of the Port Zone include all navigable waters of the United States and contiguous land areas within the boundaries of an area starting from a point on the international boundary in Lake Erie at latitude 42°19′24″ N, longitude 80°31′10″ W, proceeding southwest along the international boundary to a point at latitude 41°40′36″ N, longitude 82°25′00″ W; thence south to latitude 41°00′00″ N; thence east to longitude 78°54′58″ W; thence north to latitude 42°00′00″ N; thence east to the east bank of the Delaware River at latitude 42°00′00″ N, longitude 75°21′28″ W; thence east to longitude 74°39′00″ W; thence north to the international boundary at a point at latitude 44°59′58″ N, longitude 74°39′00″ W; thence southeast along the international boundary to the starting point.

Sector Lake Michigan's office is located in Milwaukee, WI. The boundaries of Sector Lake Michigan's Marine Inspection Zone and Captain of the Port Zone include all navigable waters of the United States and contiguous land areas within the boundaries of an area starting from a point at latitude 44°43′00″ N, longitude 84°30′00″ W, proceeding due west to longitude 85°40′00″ W; thence northwest to the eastern shore of Lake Michigan at latitude 45°01′00″ N; thence northwest to latitude 45°22′30″ N, longitude 86°19′00″ W; thence northeast to latitude 45°41′00″ N, longitude 86°06′00″ W; thence northwest to latitude 46°20′00″ N, longitude 87°22′00″ W; thence west to latitude 46°20′00″ N, longitude 90°00′00″ W; thence south to latitude 41°00′00″ N; thence east to the Ohio-Indiana border at latitude 41°00′00″ N, longitude 84°48′12″ W; thence north along the Ohio-Indiana border to the intersection of the Ohio-Indiana-Michigan border at latitude 41°41′59″ N, longitude 84°48′22″ W; thence east along the Ohio-Michigan border to latitude 41°42′13″ N, longitude 84°30′00″ W; thence north to the start point.

Sector Detroit's office is located in Detroit, MI. The boundaries of Sector Detroit's Marine Inspection Zone and Captain of the Port Zone include all navigable waters of the United States and contiguous land areas within the boundaries of an area starting from a point at latitude 41°00′00″ N, longitude 84°48′12″ W on the Ohio-Indiana boundary, proceeding east to longitude 82°25′00″ W; thence north to the international boundary in Lake Erie at latitude 41°40′36″ N, longitude 82°25′00″ W; thence north along the international boundary to latitude 44°43′00″ N in Lake Huron; thence due west to latitude 44°43′00″ N, longitude 84°30′00″ W; thence south to the Michigan-Ohio boundary at latitude 41°42′13″ N; thence west along the Michigan-Ohio boundary to the Ohio-Michigan-Indiana boundary at latitude 41°41′46″ N, longitude 84°48′22″ W; thence south along the Ohio-Indiana boundary to the starting point.

Sector Northern Great Lakes' office is located in Sault Ste. Marie, MI. A subordinate unit, Marine Safety Unit (MSU) Duluth, is located in Duluth, MN.

(a) Sector Northern Great Lakes' Marine Inspection Zone and Captain of the Port Zone comprise all navigable waters of the United States and contiguous land areas within an area starting from a point at latitude 44°43′00″ N on the international boundary within Lake Huron; proceeding due west to longitude 85°40′00″ W; thence northwest to the eastern shore of Lake Michigan at latitude 45°01′00″ N; thence northwest to latitude 45°22′30″ N, longitude 86°19′00″ W; thence northeast to latitude 45°41′00″ N, longitude 86°06′00″ W; thence northwest to latitude 46°20′00″ N, longitude 87°22′00″ W; thence west to the Minnesota-North Dakota boundary at latitude 46°20′00″ N, longitude 96°36′30″ W; thence north along the Minnesota-North Dakota boundary to the intersection of the Minnesota-North Dakota boundary and the international boundary at latitude 49°00′02″ N, longitude 97°13′46″ W; thence east along the international boundary to the starting point; and in addition, all the area described in paragraph (b) of this section.

(b) The boundaries of the MSU Duluth Marine Inspection and Captain of the Port Zones comprise all navigable waters of the United States and contiguous land areas within an area starting at a point latitude 46°20′00″ N, longitude 88°30′00″ W, proceeding west to the Minnesota-North Dakota boundary at latitude 46°20′00″ N, longitude 96°36′30″ W; thence north along the Minnesota-North Dakota boundary to the intersection of the Minnesota-North Dakota boundary and the international boundary at latitude 49°00′02″ N, longitude 97°13′46″ W; thence east along the international boundary to a point at latitude 47°59′23″ N, longitude 87°35′10″ W; thence south to a point near Manitou Island Light at latitude 47°25′09″ N, longitude 87°35′10″ W; thence southwest to a point near the shore of Lake Superior at latitude 46°51′51″ N, longitude 87°45′00″ W; thence southwest to the point of origin.